Class 3 Lecture Demo

Class 3 Lecture Demo

Class 3 Agenda:

• Link to Agenda

Class 2 Student Submissions:

• Link to Submissions

Class 3 Themes:

1. Cartographic principles:

Cartographic Principles

2. Reference Maps vs Thematic Maps

3. Map Scale

Map Scale

Thematic strategies Dot Density, Categorical Symbolization & Proportional Symbolization

• Nominal vs continuous data types:

Symbolization- Qualities vs Quantities

• John Snow Cholera Map - 1 to 1 relationship:
  • 1 coffin = 1 death. This is NOT an example of Dot Density (dot density will be demonstrated in Class 3 | Lab 2):

John Snow Cholera Map

• US Census data - 1 to many relationship:
  • 1 categorized dot = many persons per racial category:

Dot Density

• Map Scale
  • Representative Fraction
  • Verbal Scale
  • Bar Scale

Map Scale Expressions

Class 3 Demonstration Labs:

Demo Data:

• Download Link to Class 3 demo data for all 4 labs

QGIS Lecture Demo 1 - Spatial Bookmarks + Scale + Map Generalization

Utilize bookmarks.demo.qgs

Spatial Bookmarks can be placed in either Project Bookmarks, or in User Bookmarks

Simplify Features (Map Generalization)

QGIS Lecture Demo 2 - Select by Attributes (Natural Earth - Populatated Places) vs Selection by Location (Natural Earth - Countries & Populated Places)

Utilize selection.demo.qgs

1. Select by Attribute:

Select By Attribute Expression

SQL Expression within Populated Places

Resulting Selection in Populated Places

2. Select by Location:

Select by Location Parmeters

Select by Location Result

QGIS Lecture Demo 3 - Proportional Symbolization

Utilize selection.demo.qgs

• Set project CRS to 3576
• Import 2 instances of russia.populated.places
• Set Size Assistant to GN_2020
• Set Categorization to TIMEZONE
• Enact Data Defined Legend
• Lock Legend Item & Layers
• Lock Map Item & Layers
• Auto Update Toggle off in Legend Item
• Copy Symbolization from first layer to second layer as needed
• Finalize Map Layout Design and Export

Population Proportionality set in Size Assistant

Categorization to TIMEZONE

Data Defined Legend on GN_POP

Lock Legend

Final Layout Items

QGIS Lecture Demo 4 - Map Insets - Multiple Frames + Layer Groups

Utilize bookmarks.demo.qgs

• Map layout elements: scale bars, map insets, complex legends & labels

Map Layout Elements

• Spatial Bookmarks & Inset Maps

Map Layout Setup for Inset Maps

QGIS Lecture Demo 5 - Map Scale & Scale Bars

Utilize scale.demo.qgs

Map Canvas - One Mile Polyline for Testing Scale Text and Scale Bar

Map Layout - Scale Bar Set to 1 mile with Multiplier Set to 1; Fixed Width Set to 1 Unit